[PATCH 1/1] Add available memory ioctl for libhsakmt

[Daniel Phillips]

From: Daniel Phillips <dphillip at amd.com>

Add an ioctl to inquire memory available for allocation by libhsakmt
per node, allowing for space consumed by page translation tables.
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h      |  1 +
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c    | 14 ++++++++++++++
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c        | 17 +++++++++++++++++
 include/uapi/linux/kfd_ioctl.h                  | 14 ++++++++++++--
 4 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index fcbc8a9c9e06..64c6c36685d3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -266,6 +266,7 @@ int amdgpu_amdkfd_gpuvm_acquire_process_vm(struct amdgpu_device *adev,
 void amdgpu_amdkfd_gpuvm_release_process_vm(struct amdgpu_device *adev,
 					void *drm_priv);
 uint64_t amdgpu_amdkfd_gpuvm_get_process_page_dir(void *drm_priv);
+size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev);
 int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
 		struct amdgpu_device *adev, uint64_t va, uint64_t size,
 		void *drm_priv, struct kgd_mem **mem,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 86a1a6c109d9..b7490a659173 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -190,6 +190,20 @@ static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev,
 	return ret;
 }
 
+size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev)
+{
+	uint64_t reserved_for_pt =
+		ESTIMATE_PT_SIZE(amdgpu_amdkfd_total_mem_size);
+	size_t available_memory;
+
+	spin_lock(&kfd_mem_limit.mem_limit_lock);
+	available_memory =
+		adev->gmc.real_vram_size -
+		adev->kfd.vram_used - reserved_for_pt;
+	spin_unlock(&kfd_mem_limit.mem_limit_lock);
+	return available_memory;
+}
+
 static void unreserve_mem_limit(struct amdgpu_device *adev,
 		uint64_t size, u32 alloc_flag)
 {
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 4bfc0c8ab764..5c2f6d97ff1c 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -486,6 +486,20 @@ static int kfd_ioctl_get_queue_wave_state(struct file *filep,
 	return r;
 }
 
+static int kfd_ioctl_get_available_memory(struct file *filep,
+			         struct kfd_process *p, void *data)
+{
+	struct kfd_ioctl_get_available_memory_args *args = data;
+	struct kfd_dev *dev;
+
+	dev = kfd_device_by_id(args->gpu_id);
+	if (!dev)
+		return -EINVAL;
+
+	args->available = amdgpu_amdkfd_get_available_memory(dev->adev);
+	return 0;
+}
+
 static int kfd_ioctl_set_memory_policy(struct file *filep,
 					struct kfd_process *p, void *data)
 {
@@ -1959,6 +1973,9 @@ static const struct amdkfd_ioctl_desc amdkfd_ioctls[] = {
 
 	AMDKFD_IOCTL_DEF(AMDKFD_IOC_SET_XNACK_MODE,
 			kfd_ioctl_set_xnack_mode, 0),
+
+	AMDKFD_IOCTL_DEF(AMDKFD_IOC_AVAILABLE_MEMORY,
+			kfd_ioctl_get_available_memory, 0),
 };
 
 #define AMDKFD_CORE_IOCTL_COUNT	ARRAY_SIZE(amdkfd_ioctls)
diff --git a/include/uapi/linux/kfd_ioctl.h b/include/uapi/linux/kfd_ioctl.h
index af96af174dc4..94a99add2432 100644
--- a/include/uapi/linux/kfd_ioctl.h
+++ b/include/uapi/linux/kfd_ioctl.h
@@ -32,9 +32,10 @@
  * - 1.4 - Indicate new SRAM EDC bit in device properties
  * - 1.5 - Add SVM API
  * - 1.6 - Query clear flags in SVM get_attr API
+ * - 1.7 - Add available_memory ioctl
  */
 #define KFD_IOCTL_MAJOR_VERSION 1
-#define KFD_IOCTL_MINOR_VERSION 6
+#define KFD_IOCTL_MINOR_VERSION 7
 
 struct kfd_ioctl_get_version_args {
 	__u32 major_version;	/* from KFD */
@@ -98,6 +99,12 @@ struct kfd_ioctl_get_queue_wave_state_args {
 	__u32 pad;
 };
 
+struct kfd_ioctl_get_available_memory_args {
+	__u64 available;	/* from KFD */
+	__u32 gpu_id;		/* to KFD */
+	__u32 pad;
+};
+
 /* For kfd_ioctl_set_memory_policy_args.default_policy and alternate_policy */
 #define KFD_IOC_CACHE_POLICY_COHERENT 0
 #define KFD_IOC_CACHE_POLICY_NONCOHERENT 1
@@ -742,7 +749,10 @@ struct kfd_ioctl_set_xnack_mode_args {
 #define AMDKFD_IOC_SET_XNACK_MODE		\
 		AMDKFD_IOWR(0x21, struct kfd_ioctl_set_xnack_mode_args)
 
+#define AMDKFD_IOC_AVAILABLE_MEMORY		\
+		AMDKFD_IOR(0x22, struct kfd_ioctl_get_available_memory_args)
+
 #define AMDKFD_COMMAND_START		0x01
-#define AMDKFD_COMMAND_END		0x22
+#define AMDKFD_COMMAND_END		0x23
 
 #endif
-- 
2.34.1